The present invention relates to a respiratory tube capable of regulating air-blowing pressure, in which a specifically designed damper board is disposed in an intake tube of the respiratory tube, whereby the direction and pressure value of the blown in air are adjustable in accordance with the requirements of different users.
FIG. 5 shows the structure of a conventional respiratory tube used in diving, which includes a respiratory tube main body la and an intake tube 2a connected with each other. A blowing manifold 3a is disposed on one side of the intake tube 2a for a user to hold in the mouth and breathe. However, it is known in diving field that when a diver deeply dives into water and then buoys out of the water, the diver must blow out the water accumulating in the respiratory tube by a blowing pressure. However, according to the structure of the conventional respiratory tube, a check membrane valve 4a is disposed on the bottom of a lower section of the respiratory tube so that the accumulating water can be only exhausted and cannot flow back into the respiratory tube. The other end of the respiratory tube is an open end ( not shown ) enabling the accumulating water to be exhausted and a user to normally breathe. Therefore, when the user blows air into the respiratory tube to exhaust the accumulating water, a part of the water will be downward exhausted through the membrane valve 4a and the other part of the water will be upward exhausted through the open end. However, the pressure of the air blown by the user into the respiratory tube is unified and the membrane valve 4a of the respiratory tube is subject to water pressure and the resistance against exhaustion of the water is increased so that in fact, most of the accumulating water is exhausted from the upper open end. The length from the intake tube 2a to the upper open end is longer. According to pressure principle, the blowing pressure will be correspondingly increased. Therefore, for a beginner or a female user, the blowing pressure is often insufficient and thus the accumulating water is often not totally exhausted and is sucked into the mouth to cause danger. It is necessary to solve this problem so as to ensure safety.